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Unread 27-09-2014, 11:09
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AKA: Tim
FRC #3132 (The Thunder Down Under)
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Re: 2015 Beta Testing - The Components are Here.

Quote:
Originally Posted by Ether View Post
The integral of 60 amps for 2 minutes would be the same as 2 amps for one hour. Would the effect on battery charge be the same?
At 60 amps you would get more losses through heat/resistance (P = I^2*R), including losses to the internal resistance of the battery? However the PDP will only let us get a measurement on the power being used by the robot, not the losses of the battery's internal resistance and it's cabling. ie the charge will be the same iff heat losses are zero. Whether this will be anything more than negligable however, I don't know.

Is it possible to get a good idea of the battery's initial condition from measuring it's voltage and internal resistance? If not what other information would you need? I know the battery beak does this and gives a percentage, but how accurate is this? Potentially you could have a system where you plug in a battery, measure it's characteristics before the match start and then do the intergral throughout the match to get the state of charge. This assumes that the power draw by the RoboRIO/PCM/VRM can be assumed constant or estimated accurately.

Finally what would you use this for? I'm not sure but it's 1am here and I'm bored and speculative
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FIRST® Team 3132 - The Thunder Down Under
Sydney, Australia
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